This invention relates generally to muscle training and therapeutic equipment and, more particularly, to a training device to train and strengthen the external rotator muscles of a person's shoulder. Use of the present invention directly stimulates the stretch shortening cycle in the external rotators to allow for more motor unit recruitment after a rapid stretching of the external rotators, further increasing the benefits of rotational exercise.
Athletes, as well as other individuals, who experience repetitive rotational stress on the shoulder(s) are benefitted by exercises that stretch and strengthen rotational muscles of the shoulder. The external rotator muscles of the shoulder (Supraspinatus, Infraspinatus, and Teres Minor) are prone to injury. For instance, baseball pitchers often experience fatigue or injury to the rotator cuff of a shoulder due to stresses placed on external and internal rotators. The lack of flexibility and muscular balance of muscles in the shoulder often leads to injury.
Various devices have been used in the past to stretch or train shoulder muscles. For instance, kettle bells and dumbbells use gravity to apply force upon shoulder muscles. These devices and corresponding methods use gravity to apply force but do not provide stress upon the external rotators at the shoulder until rotation has started. Unfortunately, this does not properly replicate the stresses experienced with the rotational motions associated with certain activities, such as pitching.
Therefore, it would be desirable to have a training device to train the external rotator muscles of the shoulder in both eccentric (produces force as the muscle lengthens) and concentric (produces force as the muscle shortens) muscle actions. Further, it would be desirable to have a training device that directly stimulates the stretch shortening cycle of the external rotators to allow for more motor unit recruitment after a rapid stretching of the external rotators, further strengthening the muscles stimulated.